Crawl space excavation

[DKinWA]

I was out looking at a project today and the homeowner asked me if I'd do some excavating under his house. There's about 12 - 18 inches of crawl space and needs to open it up to 24. The house is about 1600 square feet and only one access point through the foundation. I told him I'd have to think about it, but any ideas on how you'd do this? I did a quick and dirty estimate, and I figure it'd be about 40 yards. One thought was a couple of small conveyors and a couple of financially motivated high school kids with small shovels and rakes I probably won't take this one on, but it did get me thinking.

 

[BKrois]

They make mini excavators that are 36" or less wide, if they rent them locally in your town that might be worth looking into as your could walk it down stairs to the crawl space.

If conveyors or wheel barrels don't work, you can always use 5 gallon pails.....

 

[Steve Frazier]

I'm curious what this 6" will gain the homeowner!!:beatsme

I think conveyors are the best bet, you can move quite a bit of material with them. Place a small loader of some sort at the end outside so you can move the dirt easily to where you need it.

I'd take something like this, but it sure would have to be worth my while!

 

[DKinWA]

It's probably going to be closer to an additional 12", but they need the clearance for the duct work for the heat pump. It's an older home and it's not feasible to run the duct work anywhere but in the crawl space. I keep thinking of the hassle and it's definitely going to have to be worth my time to get me to do it. The more I think about it, it might make more sense to jack the house up and add a couple rows of block to the foundation?

 

[Dwan Hall]

Keep that brain working. jacking up the house is an option. So would be digging along side the house until you were deep enough to start digging under it with equipment in turn giving them a basement when finished. or you could insulate the perimeter and make the complete crawl space part of the duct work. I have done the bucket routine and it took 1 year in my spare time to do my dads house so I would have a room to live in for myself.

 

[cat320]

Your first idea was the one motivated kids and a conveyour belt into your dump.Look at it this way though a really high number out there if they really want it done they will pay it .Because sometimes the biggest pain in the neack job turn out to be the pot of gold because no one else wanted to bid on it. think about it.We had a job that was a pain and figured it acordingly but found out later that we were the only co. that actuly put a bid in on it after seeing it.We could of got a hell of alot more

 

[littledenny]

This may be a dumb question, but how deep is the foundation in relation to the present/proposed new grade? I'd be a bit worried about undermining the foundation if you're going to lower the entire space.

Considered just lowering the path necessary to install the new work? Considered the possibility of potential new ground moisture/ground water problems?

My recent experience in this regard was placing a layer of gravel under several "weekend places" on creeks in the area. Running water from recent floods washed through several crawlspaces, and my "boss" sold several couples on the idea of placing 6-8 inches of gravel under these houses, to catch sand during the next wash, as a means of stablizing the crawlspace elevation.

I'm a little dubious on the whole idea, but what the heck, I'm the employee here. Actual method was to place gravel through the crawl space access with a small loader, than rake or bucket the gravel across the crawlspace. Wasn't a fun job, but went quicker that I thought it would. We've done three 800-1200 foot spaces in three long mornings, him running the loader, me running the rake. (Add in the hottub time for crew recovery, as it's really hard on the body to rake gravel while squatting, or laying on your belly.)

While these projects were fill ins, rather than a dig as you're considering, I'd think the motions wouldn't be much different. Unless you already have access to a conveyer that would shift around easy enough to move over 4 feet occasionally, I'd simply recommend the two kids and the five gallon bucket option rather than spending hours inventing a conveyor. Might dig faster that you'd think.

 

[cat320]

They rent them around here in nominal lenghts that can be linked together.Well worth the time if you have alot to move and an no space to move in. Bucket would a last resort for me but alot more time consuming and more labore involved to move buckets. good question about under mining the foundation but I would think it must be well enough into the ground for frost as most crawl spaces that I have done are filled in abit after backfill.

 

[DKinWA]

Another idea I thought of was using one of the big vac trucks with a length of hose. I could loosen up the soil and then vacum it out. Undermining the foundation wouldn't be an issue since its a short stemwall on a footing. The soil under the foundation is very stable and would support a much bigger structure than what's there. Water isn't an issue either since the footing drains take care of any surface water before it gets to the crawl space.

I thought about just digging where the duct work goes, but they need the work space to do the other insulation work they plan to do. They're going to insulate between the floor joists and put plastic down as part of the heating package.

BTW, I'm about 30 minutes from the washington coast, so frost concerns are non-existent. A cold snap for us is temps in the teens for a couple of days. Thanks for the ideas and I'll take more if you have them. Happy New Year

 

[Dwan Hall]

I never thought of the vac truck. I have one and from my experiance it would work if you ran smooth walled pipe to it but the flex pipe tends to stop the flow enough to plug. and you have to feed it evenly but would be worth a try. ware ear protection as they are load. and bigger is better

 

[badranman]

Hey Dk, just wondering how you're coming along with this project? A bit different so I was kinda curious as to your progress.

 

[DKinWA]

I had to pass on the project. I came home sick on the fourth and have been off work since then. This stuff has been nasty and I'm still not 100%, but I'm going to work on tuesday come hell or high water. After this most recent go around, I think I may reconsider and get a flu shot next year.

 

[littledenny]

Luck of the draw?

FWIW - in the Army, we were forced to take flu shots, and I got it everytime. The few times I managed to be out of town on shots day, never got it that season.